SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c2ac54fd522af38d087db83bac8f1b3975c5bfd8e322c818d472db06e041ec02' 
  AND token = 'gUrkcYoTfbbfVl8LDK43O8aiQFPXUYJENorujBwBZS8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}